Laying oriented fibrous webs

Abstract

A process and apparatus for laying highly ordered webs wherein a fibrous strand forwarded towards a collecting surface is caused to oscillate up to an amplitude equal to the desired web width and by passing between two closely spaced plates is laid in successive courses with a very high degree of parallelism and precision. A plurality of the laying devices may be used to produce thicker or wider webs or webs having layers of differing orientation directions. Various bonding methods may be applied to the ordered webs.

We claim: 
     
       1. A process for the production of an ordered web from at least one fibrous strand, comprising forwarding a strand towards a moving collecting surface, imparting an oscillatory motion to the strand at a point above the collecting surface and passing the oscillating strand between two closely spaced plates which are substantially parallel to each other and to the plane of strand oscillation and which extend substantially from the place of oscillation down to the collecting surface whereon the strand is laid in substantially parallel successive lengths of the strand. 
     
     
       2. A process according to claim 1 wherein the collecting surface is advanced during the laying process and the strand is laid transversely or parallel to the direction of advance of the collecting surface. 
     
     
       3. A process according to claim 1 wherein two or more strand laying devices are used together to lay the desired web thickness or width. 
     
     
       4. A process according to claim 1 wherein the ordered 20 web is bonded by adhesive, thermal or stitching means. 
     
     
       5. Apparatus for laying down a fibrous strand in substantially parallel courses comprising means for supplying a fibrous strand, means for forwarding the strand, means to impart an oscillatory motion to the forwarded strand and a collecting surface adapted to move relative to the strand oscillatory means and whereon the strand is laid and including two closely spaced plates which are substantially parallel to each other and to the plane of oscillation and which extend between the oscillating means and the collecting surface. 
     
     
       6. Apparatus according to claim 5 wherein the strand is forwarded and oscillated by gaseous fluid jets and some of the issuing gas is passed down between the plates. 
     
     
       7. Apparatus according to claim 5 wherein the plates are perforated. 
     
     
       8. Apparatus according to claim 5 wherein a static eliminating device is positioned before the plates close to the strand path. 
     
     
       9. Apparatus for laying one or more webs of substantially parallel fibrous strands wherein two or more devices according to claim 5 are used together to lay the desired web thickness or width on a single collecting surface.